diff --git a/.github/pull_request_template.md b/.github/pull_request_template.md
new file mode 100644
index 00000000..9a01de9f
--- /dev/null
+++ b/.github/pull_request_template.md
@@ -0,0 +1,15 @@
+## Ziel
+Kurze Beschreibung des Ziels/Problems und was dieser PR löst.
+
+## Änderungen
+-
+
+## Prüfliste (Definition of Done)
+- [ ] CI grün (Backend/Docs)
+- [ ] Doku-Front‑Matter vorhanden und valide (`modul`, `status`, `summary`, optional `last_reviewed`, `review_cycle`, `yt_epic/yt_issues`)
+- [ ] Links geprüft (CI Link‑Checker läuft grün)
+- [ ] Falls relevant: YouTrack‑Key im PR‑Titel/Commit enthalten (z. B. MP-7)
+- [ ] Bei Architekturänderung: ADR aktualisiert und verlinkt
+
+## Screenshots/Notizen (optional)
+-
diff --git a/.github/workflows/ci-docs.yml b/.github/workflows/ci-docs.yml
new file mode 100644
index 00000000..0a8d3387
--- /dev/null
+++ b/.github/workflows/ci-docs.yml
@@ -0,0 +1,89 @@
+name: CI Docs
+on:
+  pull_request:
+    paths:
+      - 'docs/**'
+      - '.junie/**'
+      - '.github/workflows/ci-docs.yml'
+      - '.markdownlint.yaml'
+      - '.vale.ini'
+  push:
+    branches: [ main ]
+    paths:
+      - 'docs/**'
+      - '.junie/**'
+      - '.github/workflows/ci-docs.yml'
+      - '.markdownlint.yaml'
+      - '.vale.ini'
+
+jobs:
+  docs:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Node (markdownlint)
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+      - name: Install markdownlint
+        run: npm i -g markdownlint-cli
+      - name: Markdownlint
+        run: markdownlint 'docs/**/*.md'
+
+      - name: Setup Vale
+        run: |
+          curl -fsSL https://install.goreleaser.com/github.com/errata-ai/vale.sh | sh
+          sudo mv bin/vale /usr/local/bin/vale
+      - name: Vale
+        run: vale docs/
+
+      - name: Link Checker
+        uses: lycheeverse/lychee-action@v1
+        with:
+          args: --verbose --no-progress 'docs/**/*.md'
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Front-Matter Schema Validate
+        run: |
+          pip install pyyaml jsonschema
+          python .junie/scripts/validate-frontmatter.py
+
+      - name: Docs Drift Check
+        run: bash .junie/scripts/check-docs-drift.sh
+
+      - name: Render PlantUML
+        run: bash .junie/scripts/render-plantuml.sh
+
+      - name: Upload diagrams artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: diagrams
+          path: build/diagrams
+
+      - name: Validate YouTrack issues exist (optional)
+        if: ${{ env.YT_URL != '' && env.YT_TOKEN != '' }}
+        run: |
+          set -euo pipefail
+          KEYS=$(grep -Rho "[A-Z]\+-[0-9]\+" docs | sort -u || true)
+          if [ -z "$KEYS" ]; then
+            echo "No YouTrack keys found in docs."
+            exit 0
+          fi
+          echo "Prüfe Keys:" $KEYS
+          fail=0
+          for k in $KEYS; do
+            code=$(curl -s -o /dev/null -w "%{http_code}" \
+              -H "Authorization: Bearer $YT_TOKEN" \
+              -H "Accept: application/json" \
+              "$YT_URL/api/issues/$k?fields=idReadable")
+            if [ "$code" != "200" ]; then
+              echo "[YT] Issue nicht gefunden: $k (HTTP $code)"; fail=1;
+            fi
+          done
+          exit $fail
+        env:
+          YT_URL: ${{ secrets.YT_URL }}
+          YT_TOKEN: ${{ secrets.YT_TOKEN }}
diff --git a/.github/workflows/youtrack-sync.yml b/.github/workflows/youtrack-sync.yml
new file mode 100644
index 00000000..74855540
--- /dev/null
+++ b/.github/workflows/youtrack-sync.yml
@@ -0,0 +1,29 @@
+name: YouTrack Sync (on merge)
+on:
+  push:
+    branches: [ main ]
+
+jobs:
+  notify:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Comment to YouTrack Issue(s)
+        run: |
+          set -euo pipefail
+          KEYS=$(git log -1 --pretty=%B | grep -o '[A-Z]\+-[0-9]\+' | sort -u || true)
+          if [ -z "$KEYS" ]; then
+            echo "No issue keys in last commit message. Skipping."
+            exit 0
+          fi
+          for ISSUE in $KEYS; do
+            MSG=$(printf 'PR/Commit gemergt: %s\nRepo: %s\nCommit: %s' "${{ github.event.head_commit.url }}" "${{ github.repository }}" "${{ github.sha }}")
+            curl -sS -X POST \
+              -H "Authorization: Bearer $YT_TOKEN" \
+              -H "Accept: application/json" \
+              -H "Content-Type: application/json" \
+              "$YT_URL/api/issues/$ISSUE/comments" \
+              -d "{\"text\": \"$MSG\"}"
+          done
+        env:
+          YT_URL: ${{ secrets.YT_URL }}
+          YT_TOKEN: ${{ secrets.YT_TOKEN }}
diff --git a/.junie/scripts/check-docs-drift.sh b/.junie/scripts/check-docs-drift.sh
new file mode 100644
index 00000000..0d9e7d2c
--- /dev/null
+++ b/.junie/scripts/check-docs-drift.sh
@@ -0,0 +1,30 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+err=0
+
+has() { grep -q "$2" "$1" || { echo "[DRIFT] '$2' fehlt in $1"; err=1; }; }
+miss() { grep -q "$2" "$1" && { echo "[DRIFT] Veralteter Begriff '$2' in $1"; err=1; }; }
+
+# Quelle der Wahrheit: Spring Cloud Gateway
+has docs/overview/system-overview.md "Spring Cloud Gateway"
+has docs/architecture/adr/0007-api-gateway-pattern-de.md "Spring Cloud Gateway"
+miss docs/architecture/adr/0007-api-gateway-pattern-de.md "Ktor"
+
+# C4: Container muss Technology korrekt führen
+has docs/architecture/c4/02-container-de.puml "Spring Cloud Gateway"
+miss docs/architecture/c4/02-container-de.puml "Ktor"
+
+# Verbiete versehentlich verbliebene englische ADR/C4 ohne -de
+if ls docs/architecture/adr/*.md 2>/dev/null | grep -E -v '-de\.md$' >/dev/null; then
+  echo "[DRIFT] Englische ADR-Dateien ohne -de gefunden in docs/architecture/adr/"
+  ls docs/architecture/adr/*.md | grep -E -v '-de\.md$' || true
+  err=1
+fi
+if ls docs/architecture/c4/*.puml 2>/dev/null | grep -E -v '-de\.puml$' >/dev/null; then
+  echo "[DRIFT] Englische C4-Dateien ohne -de gefunden in docs/architecture/c4/"
+  ls docs/architecture/c4/*.puml | grep -E -v '-de\.puml$' || true
+  err=1
+fi
+
+exit $err
diff --git a/.junie/scripts/render-plantuml.sh b/.junie/scripts/render-plantuml.sh
new file mode 100644
index 00000000..0f12d6aa
--- /dev/null
+++ b/.junie/scripts/render-plantuml.sh
@@ -0,0 +1,9 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+mkdir -p build/diagrams
+shopt -s nullglob
+for f in docs/architecture/c4/*.puml; do
+  docker run --rm -v "$PWD":/data plantuml/plantuml -tsvg "/data/$f" -o "/data/build/diagrams"
+  echo "Rendered build/diagrams/$(basename "${f%.puml}").svg"
+done
diff --git a/.junie/scripts/validate-frontmatter.py b/.junie/scripts/validate-frontmatter.py
new file mode 100644
index 00000000..a736dba5
--- /dev/null
+++ b/.junie/scripts/validate-frontmatter.py
@@ -0,0 +1,33 @@
+import os, re, yaml, json
+from glob import glob
+
+try:
+    import jsonschema
+except ImportError:
+    # GitHub Actions step will install this before running; provide friendlier message if missing
+    raise SystemExit("[FM] jsonschema package not installed. Please run: pip install jsonschema pyyaml")
+
+SCHEMA_PATH = 'docs/.frontmatter.schema.json'
+FM_REGEX = re.compile(r'^---\n(.*?)\n---', re.S)
+
+with open(SCHEMA_PATH, encoding='utf-8') as f:
+    schema = json.load(f)
+
+errors = 0
+for path in glob('docs/**/*.md', recursive=True):
+    # Skip generated or non-content files if any (none by default)
+    with open(path, 'r', encoding='utf-8') as fh:
+        content = fh.read()
+    m = FM_REGEX.search(content)
+    if not m:
+        print(f"[FM] fehlt: {path}")
+        errors = 1
+        continue
+    try:
+        fm = yaml.safe_load(m.group(1)) or {}
+        jsonschema.validate(fm, schema)
+    except Exception as e:
+        print(f"[FM] invalid in {path}: {e}")
+        errors = 1
+
+exit(errors)
diff --git a/.junie/vale/MoCode/ForbiddenTerms.yml b/.junie/vale/MoCode/ForbiddenTerms.yml
new file mode 100644
index 00000000..759863ae
--- /dev/null
+++ b/.junie/vale/MoCode/ForbiddenTerms.yml
@@ -0,0 +1,8 @@
+extends: existence
+message: "Veralteter Begriff: '%s'"
+level: error
+ignorecase: true
+scope: text
+nonword: true
+tokens:
+  - Ktor
diff --git a/.markdownlint.yaml b/.markdownlint.yaml
new file mode 100644
index 00000000..1215c074
--- /dev/null
+++ b/.markdownlint.yaml
@@ -0,0 +1,3 @@
+default: true
+MD013: false  # Zeilenlänge entspannt
+MD033: false  # Inline-HTML erlaubt
diff --git a/.vale.ini b/.vale.ini
new file mode 100644
index 00000000..80c02d6b
--- /dev/null
+++ b/.vale.ini
@@ -0,0 +1,5 @@
+StylesPath = .junie/vale
+MinAlertLevel = warning
+
+[*.md]
+BasedOnStyles = Vale, MoCode
diff --git a/docs/.frontmatter.schema.json b/docs/.frontmatter.schema.json
new file mode 100644
index 00000000..2d2edaec
--- /dev/null
+++ b/docs/.frontmatter.schema.json
@@ -0,0 +1,16 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "type": "object",
+  "required": ["status", "summary"],
+  "properties": {
+    "modul": {"type": "string"},
+    "status": {"type": "string", "enum": ["active", "draft", "deprecated"]},
+    "summary": {"type": "string"},
+    "last_reviewed": {"type": "string", "pattern": "^\\d{4}-\\d{2}-\\d{2}$"},
+    "review_cycle": {"type": "string", "pattern": "^\\d+d$"},
+    "yt_epic": {"type": "string", "pattern": "^[A-Z]+-\\d+$"},
+    "yt_issues": {"type": "array", "items": {"type": "string", "pattern": "^[A-Z]+-\\d+$"}},
+    "tags": {"type": "array", "items": {"type": "string"}}
+  },
+  "additionalProperties": true
+}
diff --git a/docs/api/README.md b/docs/api/README.md
index db431745..b488d119 100644
--- a/docs/api/README.md
+++ b/docs/api/README.md
@@ -1,4 +1,15 @@
-# Meldestelle REST API Documentation
+---
+modul: api-overview
+status: active
+last_reviewed: 2025-10-22
+review_cycle: 180d
+summary: Überblick und Einstieg in die REST‑APIs der Meldestelle.
+yt_epic: MP-1
+yt_issues: [MP-7]
+tags: [api, overview]
+---
+
+# Meldestelle – REST‑API Dokumentation
 
 ## Überblick
 
diff --git a/docs/api/members-api.md b/docs/api/members-api.md
index 9c3595f7..fd35688f 100644
--- a/docs/api/members-api.md
+++ b/docs/api/members-api.md
@@ -1,4 +1,15 @@
-# Members API Documentation
+---
+modul: members-api
+status: active
+last_reviewed: 2025-10-22
+review_cycle: 180d
+summary: Dokumentation der Members‑API (Endpunkte, Parameter, Beispiele).
+yt_epic: MP-1
+yt_issues: []
+tags: [api, members]
+---
+
+# Members‑API – Dokumentation
 
 ## Überblick
 
diff --git a/docs/how-to/branchschutz-und-pr-workflow.md b/docs/how-to/branchschutz-und-pr-workflow.md
new file mode 100644
index 00000000..37558912
--- /dev/null
+++ b/docs/how-to/branchschutz-und-pr-workflow.md
@@ -0,0 +1,49 @@
+---
+modul: workflow-pr-branchschutz
+status: active
+last_reviewed: 2025-10-22
+review_cycle: 180d
+summary: Empfehlungen für Branchschutz, PR-Ablauf und Naming-Konventionen.
+yt_epic: MP-1
+yt_issues: []
+---
+
+# Branchschutz & Pull-Request Workflow
+
+Diese Anleitung beschreibt einen einfachen, robusten Flow für `main` mit kurzen Feature-Branches und klaren Qualitätschecks.
+
+## 1) Branch-Naming
+- Feature: `feature/<kurz-beschreibung>`
+- Bugfix: `fix/<kurz-beschreibung>`
+- Docs: `docs/<kurz-beschreibung>`
+
+Optional: Issue-Key voranstellen, z. B. `feature/MP-7-doku-konsolidieren`.
+
+## 2) Pull Request (PR)
+- PR-Titel nach Conventional Commits (kurz): `docs(api): Front‑Matter vereinheitlicht (MP-7)`
+- Beschreibung kurz mit Bulletpoints; DoD-Checkliste abhaken (Template vorhanden)
+- CI muss grün sein (Backend + Docs)
+
+## 3) Branchschutz (GitHub Einstellungen → Branches → main)
+- Require a pull request before merging
+- Require status checks to pass before merging
+  - aktivieren: `CI Docs`, `CI` (Backend falls vorhanden)
+- Require linear history
+- Require approvals: mindestens 1 (bei Solo-Projekt optional, aber empfohlen)
+- Allow squash merging only
+- Disallow force pushes, Disallow deletions
+
+## 4) Commits & YouTrack
+- Commit-Message enthält Issue-Key (z. B. `MP-7`) → erleichtert Nachverfolgung
+- In Doku-Front‑Matter `yt_epic`/`yt_issues` pflegen
+- Optional: GitHub Secrets `YT_URL`, `YT_TOKEN` setzen → CI validiert verlinkte Issues, und `youtrack-sync.yml` kommentiert beim Merge automatisch ins Issue
+
+## 5) Definition of Done (Auszug)
+- Doku aktuell (README/ADR/C4/API)
+- Front‑Matter valide (`modul`, `status`, `summary`, optional `last_reviewed`, `review_cycle`, `yt_*`)
+- Links funktionieren (CI link-check grün)
+- Tests grün
+
+## 6) Lokale Tipps
+- Vor dem Push: `markdownlint`, `vale` lokal laufen lassen (optional via pre-commit hooks)
+- kleine, häufige PRs statt großer Monster-PRs